This invention generally relates to techniques for operating a disk drive apparatus. More particularly, the present invention provides a method and apparatus for reading and writing information onto a computer disk commonly called a hard disk for storing data. Merely by way of example, the present invention is implemented using such method and apparatus with an actuating device coupled between a read/write head and support member for fine tuning the read/write head onto a data track on the hard disk, but it would be recognized that the invention has a much broader range of applicability.
Storage of information has progressed through the years. From the early days, primitive man stored information on walls of caves, as well as used writings on wood such as bamboo. Since then, people have used wood, silk, and papers as a media for writings. Paper has been bound to form books. Information is now stored electronically on disks, tape, and semiconductor devices. As merely an example, some of the early disks used magnetic technology to store bits of information in a digital manner onto the magnetic media. One of the first disk drives was discovered in the 1950's by International Business Machines of Armonk, N.Y.
Although such disks have been successful, there continues to be a demand for larger storage capacity drives. Higher storage capacity can be achieved in part by increasing an aerial density of the disk. That is, the density increases with the number of tracks per inch (TPI) and the number of bits per inch (BPI) on the disk.
As track density increases, however, the data track becomes narrower and the spacing between data tracks on the disk decreases. It becomes increasingly difficult for the motor and servo control system to quickly and accurately position the read/write head over the desired track. Conventional actuator motors, such as voice coil motors (VCM), often lack sufficient resolution and bandwidth to effectively accommodate high track-density disks. As a result, a high bandwidth and resolution second-stage microactuator is often necessary to precisely position the read/write head over a selected track of the disc. Thus, there is a need for an improved drive apparatus.